Lusatian compositor Korla August Kocor (1822 – 1904) devoted a lot of attention to case studies of folk music, not only Lusatian but also Czech, Russian, Slovakian and Polish. His earliest studies of Polish folk melodies (with Lusatian words) were composed in 1845. In years 1867 – 1868 he again devoted himself to Polish folk songs. Firstly, he adjusted two numbers for the choir and secondly - six numbers for the accompaniment of violin and piano. The material used for these works came from Juliusz Roger's compilation, edited in Wrocław in 1863. Kocor was the first composer to use this compilation.